﻿#ifndef DURON_FILEREADER_H
#define DURON_FILEREADER_H

#include <stdlib.h>
#include <memory>
#include "Network/Buffer.h"
#include "Util/ResourcePool.h"
#include "Util/logger.h"
#include "Thread/WorkThreadPool.h"

using namespace std;
// using namespace toolkit;

#ifndef MIN
#define MIN(a,b) ((a) < (b) ? (a) : (b) )
#endif //MIN

namespace toolkit {

	/**
	 * http content部分基类定义
	 */
	class HttpBody : public std::enable_shared_from_this<HttpBody> {
	public:
		typedef std::shared_ptr<HttpBody> Ptr;
		HttpBody() {}

		virtual ~HttpBody() {}

		/**
		 * 剩余数据大小，如果返回-1, 那么就不设置content-length
		 */
		virtual ssize_t remainSize() { return 0; };

		/**
		 * 读取一定字节数，返回大小可能小于size
		 * @param size 请求大小
		 * @return 字节对象,如果读完了，那么请返回nullptr
		 */
		virtual Buffer::Ptr readData(size_t size) { return nullptr; };

		/**
		 * 异步请求读取一定字节数，返回大小可能小于size
		 * @param size 请求大小
		 * @param cb 回调函数
		 */
		virtual void readDataAsync(size_t size, const function<void(const Buffer::Ptr &buf)> &cb) {
			//由于unix和linux是通过mmap的方式读取文件，所以把读文件操作放在后台线程并不能提高性能
			//反而会由于频繁的线程切换导致性能降低以及延时增加，所以我们默认同步获取文件内容
			//(其实并没有读，拷贝文件数据时在内核态完成文件读)
			cb(readData(size));
		}
	};

	/**
	 * string类型的content
	 */
	class HttpStringBody : public HttpBody {
	public:
		typedef std::shared_ptr<HttpStringBody> Ptr;
		HttpStringBody(const string &str);
		virtual ~HttpStringBody() {}
		ssize_t remainSize() override;
		Buffer::Ptr readData(size_t size) override;

	private:
		size_t _offset = 0;
		mutable string _str;
	};

	/**
	 * 文件类型的content
	 */
	class HttpFileBody : public HttpBody {
	public:
		typedef std::shared_ptr<HttpFileBody> Ptr;

		/**
		 * 构造函数
		 * @param fp 文件句柄，文件的偏移量必须为0
		 * @param offset 相对文件头的偏移量
		 * @param max_size 最大读取字节数，未判断是否大于文件真实大小
		 */
		HttpFileBody(const std::shared_ptr<FILE> &fp, size_t offset, size_t max_size);
		HttpFileBody(const string &file_path);
		~HttpFileBody() {};

		ssize_t remainSize() override;
		Buffer::Ptr readData(size_t size) override;

	private:
		void init(const std::shared_ptr<FILE> &fp, size_t offset, size_t max_size);

	private:
		size_t _max_size;
		size_t _offset = 0;
		std::shared_ptr<FILE> _fp;
		std::shared_ptr<char> _map_addr;
		ResourcePool<BufferRaw> _pool;
	};

	class HttpArgs;

	/**
	 * http MultiForm 方式提交的http content
	 */
	class HttpMultiFormBody : public HttpBody {
	public:
		typedef std::shared_ptr<HttpMultiFormBody> Ptr;

		/**
		 * 构造函数
		 * @param args http提交参数列表
		 * @param filePath 文件路径
		 * @param boundary boundary字符串
		 */
		HttpMultiFormBody(const HttpArgs &args, const string &filePath, const string &boundary = "0xKhTmLbOuNdArY");
		virtual ~HttpMultiFormBody() {}
		ssize_t remainSize() override;
		Buffer::Ptr readData(size_t size) override;

	public:
		static string multiFormBodyPrefix(const HttpArgs &args, const string &boundary, const string &fileName);
		static string multiFormBodySuffix(const string &boundary);
		static size_t fileSize(FILE *fp);
		static string multiFormContentType(const string &boundary);

	private:
		size_t _offset = 0;
		size_t _totalSize;
		string _bodyPrefix;
		string _bodySuffix;
		HttpFileBody::Ptr _fileBody;
	};

}//namespace toolkit

#endif //DURON_FILEREADER_H
